In the moduli stabilization program a la KKLT, the dilaton and the
complex structure moduli are fixed via background 3-form fluxes,
whereas the Kaehler moduli are fixed through non-perturbative effects
such as Euclidean M5/D3-brane instantons and gaugino condensation.
The compactification manifold has to fulfill certain conditions on
the divisor topologies to allow the stabilization of all Kaehler
moduli. I will discuss the suitability of resolved toroidal orbifolds as
candidate models for the KKLT program, with special emphasis on the
construction of smooth Calabi-Yau manifolds from the singular
orbifold and their orientifold quotient.